Developers are consolidating around fewer mobile platforms, in grim news for platforms seeking developer traction, according to VisionMobile's "State of the Developer Nation Q3 2014" report, which tracks mobile developers and the app economy.

The average number of platforms targeted by a developer has fallen from 2.9 platforms a year ago to 2.5 platforms in the company's first-quarter report to 2.2 platforms in this survey: "If we exclude games developers, the average number of platforms targeted is just 1.75 with 43 percent of those only targeting one platform."

Predictably, Google Android and Apple iOS remain the dominant platforms, but the news was not all bad for Microsoft's Windows Phone, which is making "significant headway" with developers. Twenty-eight percent now adopt the platform even if it has not had significant market share gains as far as devices shipped. VisionMobile even found developer mind share slightly down for iOS, which translates not to fewer developers making it their primary target, but to fewer who support both Android and iOS. Top platforms by use among developers include Android (70 percent), iOS (55 percent), Windows Phone (28 percent), Windows 8 (18 percent), mobile browsers (15 percent), and BlackBerry 10 (11 percent).

But most app businesses are not sustainable at current levels, VisionMobile found, echoing similar findings on mobile app profitability. Fifty percent of iOS developers and 64 percent of Android developers earn below the app "poverty line" of $500 per month, and 24 percent of developers who are interested in making money earn nothing at all, VisionMobile found. "At the top end of the revenue scale, there are just 1.6 percent of developers with apps earning more than $500,000 per month; collectively they earn multiples of the other 98.4 percent combined."

The survey found that 67 percent of mobile app developers mostly target consumers, while 11 percent directly target professionals. The 16 percent of developers who target enterprises are twice as likely to earn more than $5,000 per app monthly and almost three times as likely to earn more than $25,000 per app per month.

In the development tools space, HTML5 was the most widely used technology, adopted by 42 percent of developers. Although 42 percent use HTML, CSS, and JavaScript, only 15 percent actually target mobile browsers. "The future of HTML5 is beyond the browser," the report said. HTML5 was followed by Java -- Android's native language -- used by 38 percent of developers.

Primary languages used include Java (26 percent), Objective-C (17 percent), and C# (14 percent). With so many developers using C#, Microsoft still has a shot to be a major force in mobile development even if it does not own the mobile OS layer, the report states. Meanwhile, 47 percent of iOS developers and 42 percent of Android developers use something other than the native language on their platforms. Hybrid apps -- HTML5 apps with a native wrapper -- are a popular non-native option for Android and iOS development, used by 14 percent of developers.